But you're Muggles! We must have a drink! What's that you've got there? Oh, you're changing Muggle money. Molly, look!
-- Arthur Weasley upon meeting Hermione's parents for the first time (CS4)
Hermione Granger’s father, a Muggle dentist (PS12, GF3). He and Hermione’s mother bring their daughter to Diagon Alley before the start of term in August, even going into Gringotts with her (CS4) and pick her up from King’s Cross each June (OP38). They have taken Hermione skiing (although she bowed out at the last minute) (OP21), camping in the Forest of Dean (DH19), and on vacation to France (PA1). Arthur Weasley is particularly fond of them, seeing as how they’re Muggles and all (CS4, OP38).
During the preparations for Harry, Ron, and Hermione’s mission to find Horcruxes, both Mr and Mrs Granger were placed under a memory modification charm. Hermione explained:
“I’ve also modified my parents’ memories so that they’re convinced that they’re really called Wendell and Monica Wilkins, and that their life’s ambition is to move to Australia, which they have now done. That’s to make it more difficult for Voldemort to track them down and interrogate them about me—or you, because unfortunately, I’ve told them quite a bit about you. Assuming I survive our hunt for the Horcruxes, I’ll find Mum and Dad and lift the enchantment. If I don’t—well, I think I’ve cast a good enough charm to keep them safe and happy. Wendell and Monica Wilkins don’t know that they’ve got a daughter, you see.” (DH6)
When the war was over, Hermione undid the memory charm and “brought [her parents] home straight away” (BLC).
Rowling on Hermione's family:
"When I first made up Hermione I gave her a younger sister, but she was very hard to work in. The younger sister was not supposed to go to Hogwarts. She was supposed to remain a Muggle. It was a sideline that didn’t work very well and it did not have a big place in the story. I have deliberately kept Hermione’s family in the background. You see so much of Ron’s family so I thought that I would keep Hermione’s family, by contrast, quite ordinary. They are dentists, as you know. They are a bit bemused by their odd daughter but quite proud of her all the same."
From Bloomsbury Live Chat after book seven:
Q: Was Hermione able to find her parents and undo the memory damage?
J.K. Rowling: Yes, she brought them home straight away.
From the Web
"Hermione Granger's father" from the Harry Potter Wiki